Technical Field
The disclosure is directed to a signal detection system for a signaling system. The invention includes embodiments of a signal detection system for a signaling system, an apparatus for use in a signal detection system for a signaling system, and a method of installing a current sensor in an existing signaling system.
Discussion of Art
At least in part due to regulations, members of the rail industry may try to implement a vehicle control system that has been referred to as an Interoperable Positive Train Control (PTC) system on railways with passenger/commuter rail traffic and on mainline railways that may transport certain materials. This regulation may provide impetus to other members of the railroad industry to implement, for example, wayside technologies that enable wireless communications of signal aspect, switch position, and hazard detector status information. Some wayside signaling locations may be controlled by relays, or controlled by equipment that cannot be easily upgraded to obtain the signal status information. In such instances, it may be feasible for sensors to be installed to sense the current in the wires to the signal lamps. Due to the large number of wayside locations that may desire such installations, it is desirable to have an efficient means for installation of a current sensor at such a location. A currently available signaling location may utilize a configuration of terminals to connect the controlling relays to the signal lamps, such as the configuration 100 shown in FIG. 1.
Referring to FIG. 1, a prior art terminal configuration 100 includes a first terminal 102 that is coupled to an earth ground; the ground provides a return path for transient currents. An arrestor 104 coupled between the first terminal 102 and a second terminal 108 may capture such transient currents. A source of the transient currents may be a lightning strike. One or more relays 106 is connected to the second terminal 108 via a relay wire 105 for providing electrical energy to control the illumination of a signal lamp (not shown). Thus, the arrestor 104 is for protecting the one or more relays 106 from a power surge. A connector 107 is coupled between, and electrically connects the second terminal 108 to the third terminal 110. A signal lamp wire 109 is coupled to the third terminal 110 for carrying an electrical signal from the relay 106 to a signal lamp. The relay wire 105 being electrically connected to the signal lamp wire 109 via the connector 107 and the second and third terminals 108 and 110, respectively. A current flow from the relay 106 via the relay wire 105 and connector 107 through the terminals 108, 110 and to the signal lamp via the signal lamp wire 109 is illustrated by the flow arrows shown in FIG. 1.
As set forth above, it may be desirable to have a system and method that improves over prior art signaling systems, or that differs from current signaling systems.